Conventional epicyclic gear trains, or planetary gear systems, include a central sun gear surrounded by one or more planetary gears. The planetary gears couple to a carrier via gear shafts or axes and mesh with an outer ring gear. During operation, for example, the sun gear provides an input rotation into the planetary gear system. In response to the rotational input, the planetary gears, and associated axes, rotate about the sun gear and, in turn, cause the outer ring gear to rotate.
Typically, manufacturers use epicyclic gear trains as part of actuation assemblies to control the movement of associated components. In the aerospace industry, for example, manufacturers utilize actuation assemblies to control the movement of aircraft wing flaps. One particular type of actuator used to control wing flap movement is a rotary actuator, such as the POWER HINGE manufactured by Curtiss-Wright. In aerospace applications, the rotary actuator functions as both a hinge that allows rotational movement of the wing flap relative to the wing of an aircraft and as an actuator that causes or creates motion of the wing flap relative to the wing.